The present invention relates to calves, and in particular to the screening of calves for passive immunity.
Newly born calves can only acquire passive immunity to disease through uptake of immunoglobulin (Ig) from colostrum. This transfer of colostral Ig is only possible within the first day of the life of the calf. Termination of the intestinal permeability occurs spontaneously at a progressively increasing rate after 12 hours postpartum. The amount of Ig transfer varies widely, and it is recognized that up to 30% of calves do not acquire adequate passive immunity. The resultant low Ig concentration is associated with a high rate of morbidity and mortality in the neonatal calf.